Each snake has its own personality. Some are easy eaters, while some are picky eaters.

Here's my advice for picky eaters based on my experience and what's worked for me.

1. Triple check your temp and humidity to ensure they are ok. Make sure there are at least 2 hides in the enclosure.
2. Ask the previous owner what he was kept in. If possible, use the same size enclosure. An enclosure that is too big for your snake can cause stress and prevent him from eating. If he was kept inside a rack, consider taping black paper or material around 3 sides of the enclosure to give him more security.
3. Handling is a no-no. Other than cage cleaning, you should not handle your snake until he's eaten at least two times.
4. Feed him inside his enclosure. Dangle and wiggle the prey in front of him for around 30 seconds. If he doesn't take it, leave the prey inside the enclosure and cover it with a blanket to give him total darkness and security. Check back in a couple of hours. If the prey is still there, remove it, and try later.
5. Wait at least 7 days in between failed feeding attempts. Do not handle him either!
6. Most important rule: You need to be patient. Snakes can go months without food, so don't worry that he will die. Hovering over him, handling him, or trying to feed him too often will only worsen the situation. Snakes are scared creatures that need an acclimation period before they are comfortable enough to eat. Give them that time and privacy!
7. After you get him eating consistently for a few months, then you can start making husbandry changes if needed.

Good luck!